You can manually connect one activity with another. By default, when you drag a new activity to the design area, a new connector automatically links the last activity to the recently added activity.
To remove the existing link between the activities, do the following:
Select the connector between two activities that you want to delete the link for.
Delete the connector using the delete key on your keyboard.
Hover over the activity that you want to create a link from, click the arrow in the center of the activity to pull a new connector, and then move the pointer to the activity to create a link.